Fix freeform window resizing.

Freeform resizing would not result in DRAG_RESIZE_MODE_FREEFORM
set, and as a result would not kick in the backdrop frame renderer.

Bug: None
Test: Backdrop renderer kicks in.
Change-Id: If962ac152186944d9643343441cf5523b832cbe8
diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index 6b1932d..96902b4 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -3071,7 +3071,7 @@
         if (task == null) {
             return false;
         }
-        if (!inSplitScreenWindowingMode()) {
+        if (!inSplitScreenWindowingMode() && !inFreeformWindowingMode()) {
             return false;
         }
         if (mAttrs.width != MATCH_PARENT || mAttrs.height != MATCH_PARENT) {